Electric Shock Mitigation Tool for PMM-Driven ESP Systems

Key Takeaways: Electric Shock Mitigation Tool for PMM-Driven ESP Systems

Executive Summary

The webinar, moderated by Kurt Abraham, Editor in Chief of World Oil, focused on the risks and solutions associated with Permanent Magnet Motor (PMM) Electric Submersible Pump (ESP) systems. Forum Energy Technologies (FET) introduced the Magna Guard, a bolt-on downhole tool designed to mitigate electric shock risks by preventing PMM-generated voltage during various operational stages. Presented by Paul Schauder, an engineering consultant with extensive experience in the ESP industry, the Magna Guard employs a dual braking system to ensure the pump shaft remains stationary, enhancing safety for field personnel. The tool is compatible with various ESP configurations and operates automatically without affecting motor performance. The webinar included a Q&A session, technical details on the Magna Guard's design, and emphasized its ease of installation and durability. The Magna Guard is expected to promote the broader adoption of PMM technology in the industry due to its robust safety features.

Speakers

Paul Shotter, Engineering Consultant- FET Multilift Solutions, Forum Energy Technologies
Moderator: Kurt Abraham, Editor-in-Chief and Chief Forecaster, World Oil

Key Takeaways

1. Magna Guard Safety: The Magna Guard is a bolt-on downhole tool designed by Forum Energy Technologies to mitigate electric shock risks in PMM-driven ESP systems by preventing voltage generation when the shaft is turned by external forces.

2. Dual Braking System: The tool features a dual braking system with a primary brake that engages by default and a secondary, servo-assisted brake for high-torque situations, ensuring the shaft remains stationary during all potential risk scenarios.

3. ESP Compatibility Assured: The Magna Guard is compatible with any manufacturer's ESP and is designed to be invisible during normal operation, ensuring no negative impact on motor performance.

4. Hydrostatic Power Conversion: The tool captures hydrostatic power from the fluid column above the pump and converts it into braking power, preventing the pump shaft from rotating when the pump is shut down, thereby protecting surface personnel.

5. Automatic Abrasive Handling: The Magna Guard is automatic, handles abrasive conditions and significant sand, and does not interfere with procedures like rocking starts, requiring no additional horsepower to disengage the brake during startup.

6. Continuous Production Testing: Tested for several months of continuous production, the Magna Guard is available in 400 and 500 series sizes, with potential future expansions, and is expected to promote the use of PMMs in the artificial lift space due to its safety benefits.

Key Quote

Permanent magnet motors do offer some significant benefits to operators in terms of versatility and efficiency. And there has been a steady uptick in operators using permanent magnet motors. But because of this risk of electric shock, that uptick of usage has been slow and the market has been looking for a way to mitigate that risk. Magna Guard is a simple bolt-on tool which endeavors to do exactly that. It's a universal tool. In other words, it can be operated and fitted to any manufacturer's ESP and is designed to eliminate the electric shock risk.

Webinar

Watch Full Webinar here.

Enhancing PMM Safety with Magna Guard: Automatic Braking for ESP Systems

Electric submersible pumps (ESPs) driven by permanent magnet motors (PMMs) offer significant advantages over traditional induction motor ESPs, including improved efficiency and versatility. Despite these benefits, PMMs pose a substantial risk of electric shock to field personnel during installation, retrieval, and maintenance. This risk arises from PMMs' ability to generate electricity even when not actively powered. To address this safety concern, Forum Energy Technologies has introduced the Magna Guard, a bolt-on tool designed to mitigate the risk of electric shock in PMM-driven ESP systems.

In addition to safety concerns, optimizing the performance of PMMs requires careful management of the braking power generated by the hydrostatic column above the pump. This braking power, measured in foot-pounds of torque, is crucial for ensuring safe and efficient motor operation, particularly during fluid equalization processes.

Title: Ensuring PMM Safety with Magna Guard

The Magna Guard is designed to provide comprehensive protection against electric shock by preventing the generation of back electromotive force (EMF) in Permanent Magnet Motors (PMMs). It is universally compatible with any manufacturer's Electric Submersible Pump (ESP) and can be easily installed without special equipment or procedures. The Magna Guard's primary function is to prevent the rotation of the PMM shaft, which can generate electricity if turned by external forces. This is especially important during operations like tripping in and out of the hole, where fluid movement through the pump stages can cause the motor to act as a generator, sending voltage up the cable to the surface.

The Magna Guard features a dual braking system with both a primary and a secondary brake. The primary brake engages by default to prevent shaft rotation during low-torque situations, such as running in and out of the hole. When the ESP is powered on, the primary brake disengages to allow normal motor operation. The secondary brake is designed for high-torque situations, such as fluid fallback during shutdown. This brake is hydrostatically assisted, using the force of the falling fluid to generate sufficient braking power to prevent shaft rotation and the subsequent generation of electricity.

Extensive testing has demonstrated the effectiveness of the Magna Guard, showing no negative impact on ESP performance. When installed, it is invisible to the ESP, meaning there is no measurable difference in pump delivery, flow, or pressure. This ensures operators can benefit from the Magna Guard's safety features without compromising their ESP systems' efficiency and performance. Additionally, its design allows for pre-installation at the workshop, simplifying the installation process and reducing the need for specialized personnel or equipment on-site.

Testing has shown that specific settings, such as having 550 feet of fluid above the pump, can generate substantial braking power. For example, this setup can create 120 foot-pounds of braking power, sufficient to keep the motor shaft stationary. This stationary state is critical as it prevents the motor from generating electricity, thereby protecting personnel working on the system. The linear relationship between the fluid column height and braking power ensures adequate braking power to meet safety requirements, even with increased fluid heights.

Tools like the Magna Guard have revolutionized the use of PMMs by addressing previous safety concerns. They are designed to fit various pump and shaft configurations, making them versatile and adaptable to different manufacturers' designs. The Magna Guard's primary advantage is its ability to automatically manage braking power without manual intervention. This feature enhances safety and simplifies PMM operation, allowing operators to focus on other critical system aspects.

A significant differentiator of the Magna Guard from existing solutions is its ability to handle dangerous situations, such as fluid fallback after a shutdown. Unlike other solutions that require manual procedures or special equipment, the Magna Guard operates automatically, ensuring continuous protection without additional steps. This automatic operation is particularly beneficial in environments where personnel safety is paramount, reducing the risk of accidents during maintenance or installation activities.

The Magna Guard marks a breakthrough in the safety of PMM-driven ESP systems by significantly reducing the risk of electric shock. This tool ensures field personnel's protection, allowing operators to maximize the benefits of PMMs without safety concerns. With its universal compatibility, simple installation, and dual braking system, the Magna Guard is a valuable asset to any ESP setup, effectively managing the risks associated with PMM-generated back EMF. As PMMs see increased adoption, the role of tools like the Magna Guard in enhancing ESP operations' safety and reliability becomes ever more vital, highlighting the ongoing need for innovation in braking power management.